NEWARK — The 19-year-old man charged with killing off-duty Newark Police Officer William Johnson late last month during a drive-by shooting pleaded not guilty this morning to murder and related charges.

The defendant, Rasul McNeil-Thomas, appeared to have a slight smile on his face as he listened to Superior Court Judge Peter Vazquez in Newark advise him of his rights. McNeil-Thomas, of Newark, is charged with murder, aggravated assault, carjacking and weapons offenses.

His public defender, John McMahon, entered the not guilty plea on behalf of his client, who remains in Essex County Jail in lieu of $1.5 million bail. McNeil-Thomas' mother and several young women were in the courtroom to support him, but were escorted outside after waving, blowing kisses and shouting words of encouragement. "Love you Rasul!" one said as she was being led out.

Johnson, 45, was ordering a slice of pizza at a Newark restaurant just before 10 p.m. on May 26, when prosecutors say McNeil-Thomas opened fire from inside the slow rolling stolen vehicle.

Johnson, who was not the intended target, died early the next morning at University Hospital. The 16-year veteran was unarmed at the time of the shooting.

A man and a woman inside the busy Lyons Avenue restaurant were also shot, but survived.

Police have said the intended target of the shooting was also inside, but that person has not been identified.

Law enforcement officials believe the shooting was payback after a group of young women fought with McNeil-Thomas' mother hours earlier outside her home, during her bridal shower.

McNeil-Thomas was arrested the next day, inside that Leslie Street house, about a half-mile from the shooting.

A second suspect has not yet been arrested. McNeil-Thomas allegedly stole the vehicle earlier that night, after pointing a gun at the driver, then forcing her out. That vehicle was used in the shooting, authorities said.

The officer's killing came during a particularly violent week in Newark, which left five people dead and 12 others wounded by gunfire. The shootings prompted police to activate a redeployment of officers to high-crime areas days ahead of schedule.

Outside the courtroom, a woman who identified herself as McNeil-Thomas' mother said he was innocent. The woman, who refused to give her name, said authorities are keeping "my son as a pawn. He's not that kind of person." She acknowledged the fight outside her house but said it had nothing to do with the shooting. She said her son plays video games and goes to church. "He's a very good kid," she said. "Free Rasul!"